In a conventional light set circuit, light emitting elements in light emitting modules connected in parallel are oriented in the same direction. Therefore, positive pins of the light emitting modules are connected to one wire and always receive a positive voltage, and negative pins of the light emitting modules are connected to another wire and always receive a negative voltage. Moreover, in the conventional light set circuit, no circuit element or module is configured to control the time when the light emitting modules emit or stop emitting lights and the light emitting period/frequency.